AC clutch relay short problem
 

I have a 2006 HCH2 and my compressor clutch won't engage. Bought a new relay but didn't solve the issue. I can jump the contacts and the clutch engages. I have 13vdc on the hot side of the coil but I also get 138 ohms to ground at that same terminal. To me this means I have some kind of short there.
I have two questions:
1. Where would I go next to trace this short? Pull the fuse panel and check the underside wiring? I'm not sure if I'm comfortable doing this.
2. If I jump the relay with spades and a tiny piece of wire to engage the clutch 24/7 what kind if ill effects would I have? Would the compressor burn up? I assume the current draw would be harmful to the battery if it sat parked like that overnight, but what if I jump it when I commute home and then take if off when I arrive. I realize this sounds foolish, but in Portland, OR I might only need the AC a dozen or so times throughout the summer.

Also I just might be way off thinking its a short at that point but none of the other relays have this 138 ohms to ground at the hot terminal.

Any help would be greatly appreciated.

Re: AC clutch relay short problem
 

Uh oh. Maybe the system is just flat and I need to recharge it. I still find it odd that i get resistance to ground on the hot terminal. I'll take my share of ridicule if I just need to put a couple cans of refrigerant in it. Straight R134-A without sealant or oil as per S Keith who I've learned a ton from trolling on here since getting this car a month ago.

Re: AC clutch relay short problem
 

I had to replace my compressor. The field coil resistance went just a touch high, and that causes the system to shut down. I could do exactly what you describe via shorting the relay.

The climate control system can be used to report climate system codes that don't show up on OBD2 as follows:

1. Turn ignition switch to LOCK
2. Press and hold AUTO and RECIRC buttoms, ignition ON, release AUTO/RECIRC buttons.

ALL LCD secments come on for 2 seconds, then the self-diag function begins.

NOTE:

• Blower motor will run at various speeds when in self-diag mode regardless of what panel is displaying.
• If there is a proble, system flashes "AUTO 88" or alternately flashes "AUTO 88" and one or more of the 14 segments in the 88 LED.
• If no problems detected, the segments will not illuminate, and the system will appear to be turned off.

To cancel the self diag, simply turn ignition to LOCK.

Refer to the following and let me know which codes you get:

https://dl.dropboxusercontent.com/u/...LIMATE_DTC.png

Re: AC clutch relay short problem
 

Ok so I did the climate system diagnosis and no codes present. I did it twice and the screen went blank after running through the test. Does this indicate I just need refrigerant then? Is there no code just for "low refrigerant pressure"?

Re: AC clutch relay short problem
 

Nope. Try adding straight 134a. Make certain there is no oil, sealant or dye. Personally, I only use a full set of manifold gages, so I can get some meaningful confirmation. They can be had for less than $50 in most cases.

Of my 3 most recent Hondas, 2x hch2 and fit, all three needed refrigerant added every 2-3 years. Typically added at the beginning of the warm season once it was noticed to be under performing.

Re: AC clutch relay short problem
 

Thanks. I'll get gauges and refrigerant. I appreciate the help.

Re: AC clutch relay short problem
 

I just bought cans from my local Walmart for $4.88 for the super tech brand. Worked like a charm.

Be very careful you don't overfill. Lots of charts available showing high/low side settings for given ambient temps.

Re: AC clutch relay short problem
 

Success! I filled with two cans of 134a and its blowing cold air again and the clutch is engaging. I jumped the clutch relay for the first can so it would draw the refrigerant in, then in reinstalled the relay which began functioning correctly, and then used the second can to get the pressure where it should be. I kept a close eye on that pressure, and when it got about where it should be the compressor began kicking on and off. Ambient temperature being 68 the compressor didn't really need to be that active I assume, even with the climate control set to lowest setting.

Re: AC clutch relay short problem
 

Good deal!

Try to check pressures again around 85-95°F whenever possible. Pretty easy to overfill at lower temps.